BALTIMORE — Alex Rodriguez hit a milestone grand slam and drove in six runs, CC Sabathia earned his first win of the season and the New York Yankees pounded the Baltimore Orioles 15-3 on Saturday night.

Rodriguez connected with the bases full against Josh Rupe in a seven-run eighth inning. It was his 22nd career slam, pushing him past Manny Ramirez into second place on the career list behind only Lou Gehrig (23).

The six RBIs also lifted Rodriguez past Carl Yastrzemski into 10th place on the career RBI list (1,847), according to Elias Sports Bureau.

Russell Martin homered twice, and Jorge Posada and Brett Gardner also connected for the Yankees, who lead the majors with 35 home runs.

Sabathia (1-1) allowed three runs and six hits in eight innings, striking out seven and walking one.

The left-hander came in with a 2.52 ERA but was winless after four starts for only the third time in his career.

Sabathia’s elusive first victory of the year came against a team he has dominated for years. In 21 starts against Baltimore, he’s 15-2 with a 2.89 ERA.

Adam Jones homered for the Orioles, who have lost 27 of their last 34 games against New York.

Brad Bergesen (0-3) gave up six runs and eight hits in six innings. He’s 0-3 with a 7.29 ERA in four career starts against the Yankees.

Four of the first five New York batters reached base in a three-run first inning. Derek Jeter singled and took third on Mark Teixiera’s fourth straight double over a two-game span. Rodriguez followed with a two-run double and Robinson Cano capped the uprising with an RBI single.

After one turn through the lineup, the Yankees produced three runs on five hits. Baltimore, in contrast, went 0 for 9 with three strikeouts.

Sabathia retired the first 11 batters before Derrek Lee singled with two outs in the fourth.

Bergesen rebounded from his shaky start to pitch well through the fifth inning, but in the sixth he gave up a single to Cano and walked Nick Swisher before Martin homered.

Jones hit a three-run drive in the seventh, but New York pulled away in the eighth against three Baltimore relievers. Posada hit a two-run shot off Jason Berken and Martin immediately followed with his sixth home run of the season. Then, after the Yankees loaded the bases against Jeremy Accardo, Rodriguez hit a 2-0 pitch into the left field seats.

Before that outburst, New York was the only team in the majors that had not scored at least four runs in an inning.

After Rupe hit Martin in the back with a pitch in the ninth, Gardner hit his first homer of the season.